This invention relates generally to junction boxes and electrical accessories thereto and more particularly to means for mounting conventional switches, outlets and the like on electrical junction boxes so that they are flush with the wall surface and securely held in place.
Electrical wiring inside building walls generally runs through conduits to junction boxes. Wall mounted electrical devices such as switches, outlets and the like are electrically connected to the wiring within the junction box and the device is mounted flush with the wall by grounding screws that pass through a metal yoke on the device and into threaded tabs on the junction box cover. A hole in the finish wall is made just large enough to admit the device. The yoke has extended ears that engage the outer wall surface around the hole as the grounding screws are drawn up so that the device assumes a predictable flush orientation relative to the surface and is held firmly thereto. A cover plate is then secured to the device for a finished appearance covering the mounting elements.
Occasionally the hole in the wall is too large and the ears cannot engage the outer wall surface. The device cannot be securely mounted in flush position without awkward measures.
Moll in U.S. Pat. Nos. 3,720,783 issued 3/13/73 and 3,651,245 issued 3/21/72 describes metallic tubular spacers that can be broken off at lines of weakness to provide adjustable spacing with a rigid metal to metal connection between yoke and junction box for secure mounting and secondary electrical grounding. Pliers can be used to snap off the unwanted portion of the tube, but two pliers should be used to ensure snapping off at the desired level. Since the tube is rigid and there is a finite distance between lines of weakening, the final length of spacer may not position the device exactly flush with the wall. Moll further provides a cover for the junction box with a fire retardant collar that extends out past the wall. This collar has break away portions that may be broken or cut away with pliers to be flush with the wall. This is an awkward and expensive assembly that increases labor costs without providing the completely flush arrangement desired.